Could you have rooted for Walter White after he left Jane to die in Breaking Bad?
Of course you couldn't. Heisenberg had plain and simply passed the point of no return, by committing an action (or, in this case, an inaction) so heinous that he irretrievably lost the sympathy of the audience.
In WWE, bad guy wrestlers pass the point of no return fairly regularly, to the point where it's pretty much impossible for fans to continue to bear their grudges against them when they decide, one day, that they want to get back on the straight and narrow.
A villain might be drawing mega-heat one week for making fun of a small child's braces, but the following week another one could put an old lady through the Spanish announcer's table just for kicks.
There's just too many people to hate, including those who are genuinely quite nice and charming most of the time, such as Rey Mysterio circa 2006, for fans to remember crimes like these for longer than a couple of months.
Thanks to the internet though, we can now go back a little further, and come to realise how ridiculous it is that certain wrestlers still manage to elicit cheers.